1. Field of the Invention
The present invention relates to a differential circuit.
2. Related Background Arts
An optical receiver generally includes a differential circuit to convert a voltage signal with the single phase configuration into two signals with the differential configuration. The differential circuit generally shows an uneven frequency response, specifically, the differential gain thereof rises about a few decibels (dB) in low frequencies below, for instance, 100 kHz. This is because of, what is called, the self-heating of active devices typically bipolar transistors implemented within the differential circuit. The present application provides techniques to compensate this unevenness observed in the differential gain against the frequency.